This two-digit digital pressure gauge was found in the 1992 special edition of Radio Electronics Experimenter. A/D converter integrated circuits are uncommon today.
This headphone amplifier using a pickup coil can be used as an extension for devices such as TVs,...
This circuit uses common components activating a control relay for the water pumps. The sensors are...
We found this circuit in a 1967 El3ectronics World. The transistors are from the era but can be...